There appears to be 3 types from my experience (now 6) and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
Added in an edit:
4. 7R III fails completely to adjust AF to a sharp change in distance
5. A9 II doesn't acquire focus in AF Wide except in the centre square
6. Back focussing in the 400/2.8 and TCs (Update: this has been found to be a lens fault in three cases.)
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience (now 6) and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
Added in an edit:
4. 7R III fails completely to adjust AF to a sharp change in distance
5. A9 II doesn't acquire focus in AF Wide except in the centre square
6. Back focussing in the 400/2.8 and TCs
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience (now 5) and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
Added in an edit:
4. 7R III fails completely to adjust AF to a sharp change in distance
5. A9 II doesn't acquire focus in AF Wide except in the centre square
6. Back focussing in the 400/2.8 and TCs
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience (now 5) and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
Added in an edit:
4. 7R III fails completely to adjust AF to a sharp change in distance
5. A9 II doesn't acquire focus in AF Wide except in the centre square
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
Added in an edit:
4. 7R III fails completely to adjust AF to a sharp change in distance
5. A9 II doesn't acquire focus in AF Wide except in the centre square
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
There appears to be 3 types from my experience and others' posted here and elsewhere:
1. Flat failure to get a lock (usually experienced with a small subject in midground)
2. Soft focus (most airtime has been about the R IV and 200-600)
3. The no-focus focus - the EVF or the EXIF shows a focus point when the actuality is fuzzy
The questions are how does Sony do hybrid AF and what's not working in these cases? I can only offer some ideas about the second question.
Sony said re the R II that AF started with phase detect sensing (PD) and completed the lock with contrast detect sensing. That makes sense (!). PD gets you into the ballpark with speed but less accuracy and CD is just the reverse (it's software analysis of contrast between neighbouring pixels and works by trial and error (except in Panasonics)).
Good light and contrast help both modes to work well and especially CDAF. If you have less than these CD takes longer and maybe simply runs out of time. The common zooms at full reach limit the light available quite a lot with apertures of f6.5 or f5.6. Add a 1.4x TC to that and there's still less light for AF to work with.
The bodies come with a settings scale of AF to Release priority and the default is 'balanced'. AF priority = don't shoot without sharp focus. Release priority = I want the shot regardless of sharpness.
When I select AF priority on the R III and A9 the fps rate with many BIF bursts drops noticeably. Down to 3 fps in a test I've just done on a setting of 10 fps on the A9.
This suggests that 'balanced' accepts soft shots.
A hi res sensor like the R III and R IV is going to show that up more readily than a 24 MP sensor on the other Alphas.
It's also of course going to better resolve subject and camera movement, lens defects and heat haze.
Sony's PD sensors are line-type only which is less accurate than cross-type. That means their contribution to AF accuracy is lower and leaves more work to CDAF, which means more time is needed. And maybe the near-enough focus standard set by 'balanced' will let through soft images with low light/contrast subjects and/or slow focussing lenses and/or high burst speeds.
So the implication for sharpness is to manage these three dimensions yourself. Eg. slow the burst rate when the light isn't good (or go to AF priority). I can happily share with you that you don't need to spend squillions to get around the problem with a 400/2.8 prime because that's the lens I've been using (mostly with a TC).
Weakness 1 I've posted about elsewhere and I can say I still don't know why it happens. You can have Small Spot AF overlapping a static bird and the AF just reaches to what's behind it. Sometimes EXIF shows a focus point and sometimes there's none. I think it's an algorithm issue and it may be a result of CDAF kicking in too soon - CDAF tends to preference the more distant lock possibility (Panasonic's last f/w update for the CDAF-only G9 included a settings option to preference near or far).
Weakness 3 a number of us have seen occasionally in the EVF - get a green box but the subject it's on is fuzzy. In my AF/Release priority testing I found it happened twice with 3 shots each time having a fuzzy subject under content the camera recorded in EXIF as being in focus.
What I was doing was slowly panning across the scene, starting with mountains, crossing the intervening palm tree and continuing with the mountains. There was 3 fuzzy shots before focus changed to the palm.
The following screen dump is of one of these shot's focus point extracted by A7info.exe from EXIF.
The purple boxes are the PDAF points that were used by the body and the white circle is the focus point decided by the camera.
Sep 20, 2020 at 10:16 PM
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